English

SZE Observables, Pressure Profiles and Center Offsets in Magneticum Simulation Galaxy Clusters

Cosmology and Nongalactic Astrophysics 2017-11-01 v1

Abstract

We present a detailed study of the galaxy cluster thermal \ac{sze} signal YY and pressure profiles using {\it Magneticum} Pathfinder hydrodynamical simulations. With a sample of 50,000 galaxy clusters (M500c>1.4×1014MM_{\rm 500c}>1.4\times10^{14} \rm M_{\odot}) out to z=2z=2, we find significant variations in the shape of the pressure profile with mass and redshift and present a new generalized NFW model that follows these trends. We show that the thermal pressure at R500cR_{\rm 500c} accounts for only 80~percent of the pressure required to maintain hydrostatic equilibrium, and therefore even idealized hydrostatic mass estimates would be biased at the 20~percent level. We compare the cluster \ac{sze} signal extracted from a sphere with different virial-like radii, a virial cylinder within a narrow redshift slice and the full light cone, confirming small scatter (σlnY0.087\sigma_{\ln Y}\simeq 0.087) in the sphere and showing that structure immediately surrounding clusters increases the scatter and strengthens non self-similar redshift evolution in the cylinder. Uncorrelated large scale structure along the line of sight leads to an increase in the \ac{sze} signal and scatter that is more pronounced for low mass clusters, resulting in non self-similar trends in both mass and redshift and a mass dependent scatter that is 0.16\sim0.16 at low masses. The scatter distribution is consistent with log-normal in all cases. We present a model of the offsets between the center of the gravitational potential and the \ac{sze} center that follows the variations with cluster mass and redshift.

Keywords

Cite

@article{arxiv.1612.05266,
  title  = {SZE Observables, Pressure Profiles and Center Offsets in Magneticum Simulation Galaxy Clusters},
  author = {Nikhel Gupta and Alex Saro and Joe Mohr and Klaus. Dolag and Jiayi Liu},
  journal= {arXiv preprint arXiv:1612.05266},
  year   = {2017}
}

Comments

20 pages, 15 figures, submitted to MNRAS